1. Field of the Invention
This invention relates to animal feed minerals and methods for their preparation in effective and economical forms. More particularly, it relates to a method of preparing a new composition of anionic salts by the metathetical reaction of magnesium and calcium chlorides with a molecular excess of ammonium sulfate to form a safe, palatable, homogeneous, particulate anionic salt composition, comprising magnesium and calcium sulfates, ammonium chloride, and ammonium sulfate. The invention also relates to the new composition formed which is effective as a supplement for feeding ruminant animals.
2. Description of Related Art
For optimum performance of commercial animals, the mineral composition of the feed rations which they receive must be formulated to correspond accurately to the nutritional needs. These needs are important with ruminant animals, and particularly critical and changeable with dairy cows. Dairy scientists have developed a term, Dietary Cation Anion Balance, which measures whether the mineral content of feed rations is positive or negative, positive indicating an excess of strong cations, and negative indicating an excess of strong anions.
The dairy cow's needs for predominantly cationic or anionic minerals varies widely depending upon the status of the animal. For example, cation rich minerals may need to be added to the diets of lactating cows. Cationic salts are used for this purpose. The most common ones are sodium bicarbonate, sodium carbonate, potassium bicarbonate, and potassium carbonate.
Until recently dry cow nutrition has been a neglected area of dairy cow nutrition. It has been reported that this approximately 60 day feeding period is very important and sets the stage for subsequent lactation performance.
Recent work by dairy scientists has shown a positive response in cows to feeding anionic salts in an acidogenic diet in the 3-6 week dry period prior to calving, with the benefits defined as decreased incidence of milk fever and hypocalcemia, increased milk production, and improved reproductive performance. The surplus of strong anions over strong cations results in a series of physiological events, which might be described as the anionic effect. Some of these events are listed as follows: increased calcium absorption in the intestines, mobilization of calcium in the bones to help neutralize the strong anions fed, and reduced blood pH.
Compounds found to effectively and economically supply strong anions for mineral feed supplements are compositions combining magnesium sulfate, calcium sulfate, ammonium sulfate and ammonium chloride. In the present practice of dairy feed supplementation, two or more of these salts are physically blended to form an anionic salt mixture for addition to cattle feed rations, or for storage. Although these physical mixtures, when adequately blended, are nutritionally effective, they exhibit poor handling, storage and use properties. The fact that they are not homogeneous causes problems of poor palatability and the hazard of inaccurate formulation.
The economics of using the physical mixtures are adversely affected by the necessity of purchasing and mixing the individual salts, particularly the costly ammonium chloride and magnesium sulfate. Both compounds are deliquescent. Depending upon the salts used and the effectiveness of their blending, some of the blend may be quite acid or ammoniacal, and unpalatable to the consuming animals. When some of the salts, such as ammonium chloride, are separated as powders, lumps, or solutions, the mixture becomes unpalatable to ruminant animals.
To fulfil practical utilization of the improved procedure of the dairy scientists, a method has been needed for producing a new anionic salt composition which is physiologically effective, palatable, storage stable, and readily handleable in commercially available equipment.
Anionic salts as described herein are salt mixtures wherein the combined strong anions outnumber the combined strong cations. Such salts react in acid manners and would normally exhibit pH's less than 7. Highly acidic salts may be unsafe and unpalatable as feed supplements so that effective anionic salt mixtures with near neutral pHs are highly desirable.
Strong ions are those ions which exert the strongest effects on acid-base balances. The important strong ions used in feed minerals comprise the cations sodium and potassium and the anions chloride and sulfate. An anionic salt mixture must contain more strong anions than strong cations. Although important to animal nutrition and buffering, weaker cations such as calcium, magnesium and ammonium, and weaker anions such as carbonate and bicarbonate, have little effect on the strong anions in the anionic salt mixture.
Magnesium and calcium chlorides are economically available sources of the important nutrients magnesium and calcium and the strong anion chloride. Ammonium sulfate, while not normally found in nature, is widely available as an economical by-product from chemical processes for nylon-6, and steel manufacturing, and provides the strong anion sulfate and the ruminant nutrient nitrogen.
The term "molecular excess of ammonium sulfate" is used herein to mean more than enough to react completely with all of the molecules of magnesium and calcium chloride.